Europe should brace itself for more small-scale attacks following the fatal blast in St. Petersburg's Metro, the EU’s anti-terrorism chief told RT, adding that Europeans will have to live with this harsh reality “for quite some time.”

“The more the physical caliphate of Daesh [Arabic pejorative term for Islamic State or IS, formerly ISIS] will be destroyed, the more the organization would want to incite people to mount small-scale attacks,” EU Counter-Terrorism Coordinator Gilles de Kerchove said.

He added that these attacks may take place in Europe for “quite some time,” but they can’t be accepted “for a long period of time.”

“It [the situation] requires population be resilient. We need to keep working in different directions – prevent the process of radicalization,” he said.

IS is not the only threat, Kerchove said, adding that Europe shouldn’t “forget about Al-Qaeda, as well.”

However, Kerchove dismissed the idea of large-scale attacks coming in the future.

“I don’t believe we’ll have major attack of 9/11,” he said.

On Monday, an improvised bomb went off in a subway train carriage of the St. Petersburg Metro. Another bomb disguised as a fire extinguisher was defused by the bomb squad at another station. At least 14 people were killed and dozens injured in the explosion.

The suspect was later identified as the 22-year old Akbarzhon Dzhalilov, a Russian citizen of Kyrgyz origin. Russia’s State Investigative Committee is treating the incident as a terrorist attack.

Europe – in particular Germany, France and Belgium – has been shaken by multiple terrorist attacks over the past year-and-a-half. In several cases the perpetrators had either pledged allegiance to IS or were directed by the organization, including via social media.